152 SWINE PRACTICE 



Etiology. — Undue exposure and inhalation of suspended or 

 gaseous irritants are common causes of laryngitis. In swine, as in 

 other animals, laryngitis is rarely a distinct process but is a con- 

 dition associated with inflammatory disturbances of the pharynx, 

 or trachea, and therefore the inflammatory process of the larynx is 

 frequently an extension from an adjacent structure. Chronic laryn- 

 gitis results from the same causative factors as the acute type, be- 

 ing merely extended over a longer period. 



Lesions. — Laryngitis in swine is generally of a catarrhal type and 

 may be either acute or chronic, although an occasional case of 

 croupous laryngitis occurs. The lesions observed are practically 

 identical with the usual lesions of this type of inflammation. 



Symptoms. — The principal symptom of laryngitis is a cough, 

 which is at first dry, later moist, and always painful. The cough 

 may become convulsive. In the intense acute attacks there will 

 be rise of temperature and probably inappetence. By palpation 

 the laryngeal region will be found supersensitive. 



Treatment. — Provide sanitary surroundings and if the patient is 

 inclined to eat, give sparingly of easily digested slops. Medicinal 

 treatment is so difficult to apply that frequently more harm than 

 good is the result. 



CROUPOUS LARYNGITIS AND TRACHEITIS 



Croupous inflammation of the mucosa of the larynx and trachea 

 is relatively common. It is most common in swine fed in self-feeders. 



Etiology. — The specific cause of croupous inflammation of the 

 membranes of the larynx and trachea have not been identified. The 

 primary cause of this condition is probably mechanical injury from 

 the awns or beards of barley or other grains. Such foreign sub- 

 stances are obtained by swine from ground barley in which quanti- 

 ties of awns have been left because of threshing while damp or wet. 

 Bating from self-feeders appears to favor inhalation of dust, beards, 

 etc. 



Lesions. — The principal lesion consists of a croupous exudate which 

 is a tough grayish membrane, usually found in the upper portion of 

 the trachea and the larynx. This membrane is so extensive in some 

 cases that it practically fills the lumen of the trachea and larynx. 

 This membrane may become detached and lodge in the larynx, eaus- 



